Now personally, I've never heard of that acronym standing for what the mod said it stood for, but I'm not one to argue and I'll take his word for it and skip out on the (I assume?) 10% warning–which I'm not sure what that does besides making some people assume you're a scammer because you have warn (I've seen this a few times now lol).
Does warn actually do anything?
Warn doesn’t really do anything until you hit higher levels, and it just takes longer in between post times.
30% - Your user blog rights and your ability to embed YouTube videos are removed. You also may lose posting privileges in some specific forums.
50% - Your signature, avatar, profile, orb, photo gallery, and guild rights are removed.
70% - Your gold rights and private message rights are removed, as well as access to your warn logs.
100% - Your posting rights are removed.
I think even at 10% you need more time inbetween posts if I remember correctly